JPS63153270A - Mechanism for exchanging substrate in vacuum vessel - Google Patents

Abstract

PURPOSE:To shorten the waiting time in a reaction chamber and to improve productivity by taking the next substrate into a substrate exchanging chamber during the treatment of a substrate in the CVD reaction chamber and completing vacuum evacuation before the end of said treatment. CONSTITUTION:A substrate 47, 47' support 24 is provided in the substrate 47, 47' exchanging chamber 5 in which a vacuum state is maintained by closing gate valves 10, 11 in both side wall parts and opening a gate valve 6 with a binder chamber 3. The untreated substrate 47 is held imposed in an upper supporting part 58 thereof. The treated substrate 47' is then imposed in the vacuum state to the lower supporting part 59 of the support 24 by the combination of the forward and backward motion of a fork 8 in the above-mentioned chamber 3 and the vertical motion of a driving shaft 24 which moves the support 24 vertically in such a manner that said support can be stopped in prescribed plural positions. The substrate 47 is ejected in this state to the above-mentioned chamber 3 by the fork 8 and thereafter, the above-mentioned valves 10, 11, 6 are opened and closed to maintain the atm. pressure in the chamber 5. The substrate 47' is ejected by a belt 14 to a cassette 15 and the substrate 47 in a cassette 13 is carried into the supporting part 58 by a belt 12, etc. The inside of the chamber 5 is then evacuated and the above-mentioned operations are repeated.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a substrate exchange mechanism within a vacuum chamber.

[Conventional technology and its problems]

Figure 11 shows an example of a conventional mechanism for taking wafers from the atmosphere into a vacuum chamber. Through the vacuum chamber (101)
The wafer (106) sent into the vacuum chamber (101)
) The belt transport mechanism (102) installed in the υ tank (lO
t), and lift it above the seat belt position using a separately provided wafer up/down mechanism.
It then has the ability to lower the wafer (106) onto another mechanism that penetrates beneath it.

This will now be explained in more detail as follows. In other words, as shown in Figure 11, the partition pulp (
The wafer (106) to be surface-treated, which has passed through the vacuum chamber (101) and is sent into the vacuum chamber (101), is further transferred to a belt transport mechanism (102) provided in the vacuum chamber (101).
It is carried to an appropriate position by K and stopped. The partition pulp (104) is then closed, and the inside of the vacuum chamber (101) is evacuated.

Next, as shown in FIG. 11B, the belt (10
2) The wafer pusher (lO8) cabinet was located below the position where the wafer (106) was placed.
While maintaining a vacuum seal through the wafer (105), the wafer (106) is lifted up by the wafer vertical drive cylinder (103) and lifted above the belt surface.

After that, another wafer transport mechanism (107) (for example, a fork transport system such as Bi, Qua, Pu, etc.) enters below the wafer (106).

Next, as shown in Figure 11C, the wafer, pusher (
108) is lowered and another wafer transport mechanism (107
) on which the wafer (406) is transferred.

The above wafers (10
6), but the procedure for taking out the processed wafer (106) to the atmosphere is the opposite.

That is, in the conventional example described above, a wafer (10
6) is conveyed through the mechanism (7), and then the vacuum chamber (101) is transferred and the processed wafer (106) is taken out. Furthermore, the unprocessed wafer (106) is taken into the vacuum chamber (t(H) and evacuated, and then transported to the processing chamber by the mechanism (107).The wafer including the above atmospheric → vacuum exhaust cycle Take 9 out,
During the import operation, the processing room becomes inefficient due to waiting time.

To avoid this problem, a method is often used in which a vacuum chamber for taking in wafers and a vacuum chamber for taking out wafers are provided separately, but this method requires a complicated configuration of the apparatus.

In addition, when only one vacuum chamber is provided, rapid exhaust and rapid venting are usually required to speed up the exhaust cycle from atmosphere to vacuum, although it depends on the throughput of the equipment.
Last week, as I pattern sizes became smaller, it became essential to suppress particle adhesion to wafers as much as possible, and rapid exhaust or venting of the vacuum chamber, which tends to cause particles to fly up, is undesirable.

[Problem that the invention seeks to solve]

The present invention overcomes the various drawbacks of the prior art described above, and provides for loading a next wafer into a vacuum chamber while a previously loaded wafer (substrate) is being processed in the processing chamber, and further: By completing vacuum evacuation, we provide a substrate exchange mechanism in a vacuum chamber that reduces waiting time in the processing chamber and improves productivity by eliminating the time required for wafer exchange, venting, and exhaust in the processing chamber. The purpose is to

[Means for solving problems]

The above object has at least two openings in the side wall,
A substrate support that is disposed in a vacuum chamber that can be opened and closed by a gate valve, and that has at least two levels of substrate support sections above and below; the substrate support is driven so that it can be stopped at a plurality of predetermined positions in the vertical direction; a lifting and lowering drive unit that allows a surface-treated substrate to be placed on one of the two stages;
This is achieved by a substrate exchange mechanism in a vacuum chamber, which is characterized in that an unprocessed substrate can be placed on the other side.

[For production]

When an unprocessed substrate is placed on one of the upper and lower substrate supports, a processed substrate is placed on the other in a vacuum state, and then the unprocessed substrate is placed on the other side. After that, the vacuum chamber is brought to atmospheric pressure, the unprocessed substrate is carried into one of the substrate supports, and the processed substrate is moved to the desired location in the atmosphere. Carry it out.

Next, the inside of the vacuum chamber is evacuated and the above-mentioned operation is repeated.

In the above series of operations, the vacuum chamber is brought to atmospheric pressure, the unprocessed substrate is carried into one of the substrate supports, the processed substrate is carried out to the required location in the atmosphere, and then the unprocessed substrate is carried into the vacuum chamber. The work of exhausting the air is completed while the unprocessed substrates that have been transported to the processing chamber first are being processed.

〔Example〕

Hereinafter, a CVD apparatus according to an embodiment of the present invention will be described with reference to the drawings.

Fig. 1 shows the whole of the present device (1), in which a pair of CVD reaction chambers (2a) (2) are provided on the left and right, and a buffer chamber (3) is provided between them.Buffer chamber (
Gate valves (4a) and (4b) are provided on the partition wall between the reaction chamber 3) and both reaction chambers (2b), and wafers are received and transferred through these gate valves.

In front of the buffer chamber (3), there is a Ueno film according to the present invention.
- An exchange chamber (5) is provided, and wafers are received and transferred between these chambers (3) and (5) via a gate valve (6).

A wafer transfer mechanism (7) is provided in the buffer chamber (3), which is equipped with a transfer fork (8), is rotatable around a central axis (9) as shown by arrow a, and It can be expanded and contracted as shown by the arrow.

Gate valves (1) are also installed on both side walls of the wafer exchange room (5).
A belt (2) for carrying in unprocessed wafers is installed on one side of the belt (2), which automatically takes out one wafer from the wafer dock and cassette (to) at a predetermined timing and transfers it to the belt (4). It is designed to be carried into the wafer exchange plan (5). In addition, a belt α◆ for carrying out processed wafers is provided on the other side, and a processed wafer dock/belt α◆ is installed.
It is designed to be carried into a cassette (G).

Next, details of the wafer exchange room (5) will be explained with reference to FIGS. 2 to 9.

The wafer exchange room (5) is a sealed tank Q1 as shown in Figure 2.
1, and as described above, it is provided with gate valve sections αυ (not shown in FIG. 2) on both side walls and gate valves (6) on the rear wall 9, and these gate valves (6)
) The details of α0αη will be described later, but the interior of the chamber is sealed by these closed states, and the interior of the chamber is kept in a vacuum or reduced pressure state by an exhaust mechanism (not shown). A substrate support C241, the general shape of which is shown in FIG.
is fixed, which extends into the atmosphere below by airtightly passing through the bottom wall of the closed tank Qυ, and is fixed to the surface of the screed engagement body. The drive shaft is supported by a vacuum seal C261 so as to be slidable in an airtight manner in the vertical direction.

The screw IJ, - engaging body (2) is screwed into the ball stopper IJ, -■, and a pulley ■ is fixed to the lower end of this screw. The motor C311 is fixed to the machine frame (not shown), and a belt (2) is wound between the pulley 1321 fixed to the rotating shaft and the above-mentioned boot IJC291. The rotation of the motor 6υ causes the ball screw to rotate, thereby moving the screw engaging body surface, and thus the drive shaft, upward or downward. The drive shaft moves upward or downward. A height sensor device (■) is provided on one side of the engaging body surface, and each height position of the drive shaft ω is detected by this, and this detection signal is used to control the motor O1.
l is driven and controlled.

As is well known, the ball screw (2) has a structure in which a ball is fitted into a threaded groove, and the drive shaft (4) can be accurately raised or lowered to a predetermined position without backlash.

A cooling water inlet and an outlet are formed in layers in the small diameter portion of the surface of the screed engaging body, and a cooling water introduction cheep (to) and a cooling water outlet channel (b) are connected to these. Although not shown in the drawings, an introduction path and an exit path are formed in the drive shaft C, and the substrate support C
I! It communicates with a circulation path formed in a meandering manner within the base c3n of 41. The substrate support (241) is made of aluminum and has excellent thermal conductivity.

As mentioned above, there is a gate valve (
6) αOQ], l are arranged and configured to airtightly close the openings (6a) (toa) (tta) formed in these side wall portions, which are schematically shown in FIG. 1 and shown schematically in FIG. The gate valve (6) is shown in detail.

First, the gate valve (6) will be explained with reference to FIG. 2. This is a structure that has already been widely used, and it mainly protrudes into the groove that opens and closes the opening (6m) and is raised and lowered by a nine-cylinder device σe. It is designed to be driven by In Figure 2, the gate body συ closes the opening (6a), but when the drive member σ2 is lowered, the gate body συ opens the opening (6a), and when the drive member σ2 is raised from now on, the opening (6a) is closed, as shown in Figure 2. The opening (6a) is closed as shown in FIG.

Next, the details of the gate valve aQ will be explained, but since the gate valve QOQll has the same configuration, only the gate valve (10) will be explained below with reference to FIGS. 3 and 4. Figure 2 is a sectional view of the main part showing the operating state of the gate valve QO.A through hole L is bored in the partition wall C that partitions the large atmospheric pressure air volume and the vacuum chamber B (Uninor exchange chamber (5)). The opening (lon) of the through hole Cυ on the vacuum chamber B side is formed to be inclined upward.

A valve plate 3 that opens and closes a valve seat formed on the periphery of the opening (log) is provided facing the opening (log), and the valve plate (43 is larger than the diameter of the wafer U). and two rods (44b) (one of which is shown in FIG. 3) extending diagonally downward through the partition wall C on both sides of the through hole C11. It is connected to a fluid pressure (hydraulic or pneumatic) drive cylinder (c) installed below with a large atmospheric pressure air volume.

The above two rods (44g) (44b) are connected to the QIJ ring (43
a) It is attached to the inside of the wall, and the rod and valve plate are sealed by welding (43b) or the like to prevent leakage from the joint. In addition, the lower end has a connecting member (
44C) is connected to the piston locked circle of the cylinder (C). In the figure, (45a) and (45b) are pressure fluid supply or discharge conduits to the cylinder, and a2 is a conveyor belt II installed in atmospheric pressure space A and vacuum chamber B, respectively, is a bearing pusher & (g). indicates 0 ring.

With the structure described above, under normal conditions, that is, when wafers are not being fed, the valve plate (43) is in a reverse pressure state, that is, the through hole (10a
) in the valve opening direction, the vacuum chamber side opening (42) of the through hole (tea) in the partition wall C is sealed. Therefore, the vacuum in the vacuum chamber B is Hole (10a)
It will not leak after passing through.

Next, when transferring the wafer (4?) sent by the conveyor belt (2) from a large atmospheric pressure air volume to the vacuum chamber B, the fluid passage of the cylinder (451) is switched and the rod 1441 ( 44M) There is no hindrance to the passage of the valve plate (43 raised, open wafer +47) via (44b),
The wafer is smoothly transferred to vacuum chamber B.

Next, when the wafer (4η) has finished moving into the vacuum chamber B, the flow path of the cylinder (451) is switched again and the valve plate (4η
3 and close the opening (lO). Note that the vacuum g
The wafer transferred into B (4η is the conveyor belt (48
1 to a predetermined position on the substrate support (241).

According to this embodiment, the driving source for operating the valve plate is provided on the atmospheric side, and all the sliding parts for operating the valve plate are located below the wafer, so that There is no fear that the resulting dust or the like will fall onto the wafer. The vacuum chamber is also not contaminated by the driving source. In addition, since the valve plate and the rod are provided at an angle with respect to the vacuum partition, it can be formed compactly, and both belts for transporting wafers in both chambers can be installed close to each other, resulting in a compact system. , workability is improved accordingly.

Note that the valve plate will resist the pressure difference and seal the opening under reverse pressure, so it is necessary to select a valve plate with sufficient rigidity and a cylinder (drive source) with sufficient thrust. There is.

In the embodiments described above, the fc structure has been described using a fluid pressure driven cylinder as the drive source for the valve plate, but it is needless to say that the present invention is not limited to this, and it is also possible to replace it with a mechanical drive mechanism.

Next, referring to FIGS. 5 to 9, the substrate support c! 41 will be explained in detail.

A fork-receiving recess that is lower than the upper surface of the substrate portion 6η of the substrate support C4 is formed, and a pair of grooves (52a) (52b) are formed in communication with the fork-receiving recess. A part of the wafer transport fork (8) is shown in FIG. 6, and the fork portions (8a) (8b) can be inserted into the grooves (52m) (52b).

A pair of parallel notches (53a) (53b) are formed over the entire height in the wafer loading side half of the substrate support (to) in a direction perpendicular to the extending direction of the grooves (52g) (52b);
In addition, a pair of parallel notches (54a) and (54b) are formed in the wafer unloading side half in alignment with these, but as clearly shown in FIGS. 6 and 8, at one end It does not span the entire height and is covered by the connecting part (G).

The notches (53a), (53b), (54a), and (54b) are aligned vertically to form the belt conveyor (56s (56b)).
(57m) and (57b) are provided, which are cut when the substrate support (to) goes up and down to form a belt conveyor (marked 4) as shown in FIG.

At the upper center of the substrate support (241), there is formed a partially annular lower substrate support part (2) and a partially circular lower base film support part (6) positioned below this and concentrically.Upper board The support part ■ has an arcuate receiving surface (as shown in Fig. 6).
58a) (58b) (s8c) (58d) (58e) (
58f), which are located on the same level, but as shown by the dashed line in FIGS. It is about to be placed. In addition, the lower board support portions are placed on the same level and have receiving surfaces (59a), (59b), (59c), (59d), and (59d) that form part of a circle, respectively.
e) At the bottom from (59f x 59g), surface-treated wafers 471' are placed on these, as shown by the dashed lines in FIGS. 7 and 8. There is.

A circular stepped hole recess is formed on the bottom of the board opening, into which the upper end of the drive shaft 5 is fitted, and is fixed with a screw or the like (not shown). ing.

The configuration of this embodiment has been described above, and the operation will now be described.

FIG. 1A and F show the height positions of the substrate support U. According to this embodiment, the substrate support (241) can take five height positions. ) and the level of the fork (8) extending and retracting from the belt conveyor (56
a) (56b) (57a) (57) The levels of In order to make the drawing easier to understand, the portion 59) is shown as U-shaped upper arm and lower arm U-shaped, respectively. (In other words, U and D are the upper support part■
is equivalent to the lower support section 61. ) Now the substrate support (2
41 indicates 1 unprocessed wafer (4
It is assumed that η is placed on the upper support portion U. In addition, the gate valves (10QIJ) on both side walls are assumed to be closed. (The gate valve (6) is open and in a vacuum state. In this state, the fork (8) extends from the buffer chamber (3) and processes 7)' is placed on the finished wafer and reaches between the upper support part U and the lower support part as shown in FIG.

Here, the substrate support c! a rises to the position shown in FIG. Processed wafers (4
is placed on the lower support part and stops at this point, and the substrate support c! The bump rises and stops at the position B in Figure 1O, where the fork (8) has moved away from the processed wafer (477) to the position shown (groove (52a) (52)).
b) in). In this position the fork (8) is retracted into the buffer chamber (3) as indicated by the arrow.

As shown in FIG. 10C, the substrate support Q41 descends and assumes the same position as the person in FIG. 10 again. The fork (8) then moves into the buffer chamber (3) as shown by the arrow in Figure 10C.
) extends into the wafer exchange chamber (5) and assumes the position shown in the figure, and the substrate support e41 moves downward and assumes the position shown in the 10th figure. As a result, the unprocessed wafer (4η) is supported by the fork (8).
) retreats to the buffer room (3).

As shown in Figure 50E, the substrate support @ moves further downward. At this position, the gate valve is closed and the wafer exchange chamber (5) is returned to atmospheric pressure. Then, the gate valve Kinsuke is opened.

When the substrate support @ stops at the position shown in Fig. 10E, processed wafers +4? )' are placed as shown. Since the gate valve αQ is opened here, the processed wafer f47
)' is transferred by a belt conveyor α through an opening (n-) and introduced into a processed wafer cassette (g).

The substrate support C4) moves further downwards and assumes the position of FIG. 1F. At this position, belt conveyor Q2 (56a)
(56b) is located above the upper support part U of the substrate support @, and at this position, the wafer A1 taken out from the unprocessed wafer dock cassette (toward) is carried by the belt conveyor (2). The substrate support Q41 is then moved upward and is again placed on the upper stage U in Figure 10. The east side of the gate valve (2) is then closed and the inside of the exchange chamber (5) is evacuated to a vacuum state.Then, as mentioned at the beginning, the gate valve (6) is opened and the fork (8) is moved into the buffer chamber. (3) Place the processed wafer 147)' in the wafer exchange box (5) and reach the position shown in Figure 1O.The above-mentioned operations are then repeated.

In addition, in the above steps, when the processed wafer (49') is placed on the lower support part, the substrate support (2
Since cooling water is circulating in the substrate portion OD of the wafer 147)', the processed and hot wafer 147)' is cooled by heat exchange with the cooling water. As a result, when the wafer is carried out from the wafer exchange chamber to the atmosphere, it can be stored in the cassette in a stable state with almost no chemical changes.

Although the embodiments of the present invention have been described above, the present invention is of course not limited thereto, and various modifications can be made based on the technical idea of the present invention.

For example, in the above embodiment, four unprocessed wafers (4) were placed on the upper support part 5, and a processed wafer t471' was placed on the lower support part 5. The number of stages of the support section is further increased, and these are divided into two groups, with unprocessed wafers placed in one group and processed wafers placed in the other group. Processed wafers and unprocessed wafers may be loaded and unloaded synchronously.In this case, a belt conveyor is required for loading and unloading depending on the number of stages. Also, although a plurality of forks are required for carrying in and out of wafers from the buffer room to the exchange room and vice versa, these 7 forks may be integrated vertically and synchronized.

Alternatively, a heating means may be provided on the upper support section to heat the unprocessed wafer placed thereon. The heated wafer may be introduced into the buffer chamber (3) and the reaction chamber (2 or 2).

Further, in the substrate support (241), a thermal insulating material is interposed between the upper support part and the lower support part, the upper support part is provided with a heating means, and the lower support part is provided with a cooling means as in the above embodiment. may be provided.

In addition, in the above embodiment, the number of height positions of the substrate support @ is five, but this number can be further increased to allow loading and unloading of wafers at each height position by a method other than the above-mentioned loading/unloading method. You may also do so. In this case, import,
The level of the belt conveyor and fork serving as the carrying-out mechanism is not limited to one level as in the embodiment, but may be provided at a plurality of levels above and below. Moreover, the carrying in and carrying out means are not limited to forks or belt conveyors, and various known means can be applied. Furthermore, in the above embodiments, processed wafers and unprocessed wafers are carried in and out through separate gate valves, but this substrate switching mechanism is carried out through a common gate valve. For example, the work of transporting processed wafers from a predetermined position in the atmosphere to a two-bar exchange chamber, carrying the wafers from a predetermined position in the atmosphere to a two-bar exchange chamber, and the accompanying venting and exhausting work are carried out in the process room. This can be done in parallel while wafers are being processed, and the time required for wafer exchange work in the processing chamber can be minimized, making it possible to further improve productivity.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the overall arrangement of a CVD apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view of the substrate exchange mechanism in the above apparatus, and FIG. 3 is a gate valve in the substrate exchange mechanism. 4 is a partial perspective view of FIG. 3, FIG. 5 is an enlarged perspective view of the substrate support in the same substrate exchange mechanism, FIG. 6 is a plan view of the same, and FIG. Figure 7 is the ■-4 line direction diagram in Figure 6, and Figure 8 is the ■-■ diagram in Figure 6.
9 is a sectional view taken along line W-E in FIG. 6; FIG. It is. FIG. 11 is a sectional view showing a conventional board exchange mechanism. In the figure,

Claims (5)

[Claims] (1) A substrate support which has at least two openings in its side wall, which is disposed in a vacuum chamber that can be opened and closed by a gate valve, and which has at least two levels of substrate support above and below; It consists of an elevating drive unit that drives the body so that it can be stopped at a plurality of predetermined positions in the vertical direction, and one of the two stages is configured such that a surface-treated substrate can be placed thereon, and an unprocessed substrate can be placed on the other. A substrate exchange mechanism in a vacuum chamber, characterized in that a substrate can be placed thereon. (2) The substrate exchange mechanism according to item 1, wherein one of the two stages is cooled. (3) The substrate exchange mechanism according to item 1, wherein the other of the two stages is heated. (4) Of the two gate valves, the gate valve that communicates with and shuts off the atmosphere has an opening on the vacuum chamber side of the through hole provided in the side wall of the vacuum chamber that is inclined upward, and opens and closes the opening. Item 1 above, characterized in that the valve plate is configured to be raised and lowered by a drive source installed on the atmosphere side via a rod extending obliquely to the atmosphere side through the vacuum partition. The board exchange mechanism described in . (5) The valve plate is formed larger in diameter than the base plate, and is connected to a cylinder installed on the atmosphere side via two rods attached to both sides of the valve plate and pulled out to the atmosphere side. The board exchange mechanism according to item 4 above.